A PDMS Self-Vortical Micromixer Without Obstructions

Abstract

Microfluidic micromixers are extremely essential components of microfluidic systems for microliter to nanoliter fluid mixing. This paper proposes a new passive micromixer called the self-vortical micromixer with no obstructions, composed of three polydimethylsiloxane (PDMS) layers. Each PDMS layer is fabricated by a PDMS replication molding process with a 150-micron height dry-film photoresist replication mold, manufactured from an organic solvent-free process. The three PDMS layers are precisely bonded together by the PDMS alignment bonding process developed in this study. This paper presents the simulation results demonstrating the self-vortical mixing phenomenon of the self-vortical micromixer with swirly flow fields and self-vortical flow fields. As the mixing test results demonstrate the mixing performance of the micromixer, the injected food dyes are completely mixed in the downstream of the mixing channel by the swirly flow fields and the self-vortical flow fields in the circular mixing chamber of the self-vortical micromixer. At Re =200, effective mixing (mixing index 0.42) can be achieved..